Surely the effect detailed below will affect ALL plans to aid Ocean mixing. The outgassing has nothing to do with the use of bubbles to move the water - the bubbles can't possibly release more gas than a comparable non-bubble technique.
A 2009/1/15 Mike MacCracken <[email protected]>: > Andrew--Greg is right--and warming of ocean near surface would also force > CO2 out, so maybe do at high latitudes where it is cold and encourage marine > life. > > Mike > > > On 1/14/09 7:25 PM, "Andrew Lockley" <[email protected]> wrote: > >> >> Any outgassing of the deep ocean water when it rose to the surface >> would only release gases added during the aeration process. Unless >> the existing ocean water was supersaturated, then there shouldn't be >> any additional outgassing. I don't have the expertise to advise >> whether there are supersaturated CO2 layers in the ocean. >> >> A >> >> 2009/1/14 Greg Rau <[email protected]>: >>> Perhaps I've missed something, but if you are advocating increased >>> ventilation of the subsurface ocean, this water is not only nutrient rich, >>> but is is also supersaturated in CO2 (relative to air). Natural ocean >>> upwelling is a huge CO2 source for the atmosphere. So unless you can show >>> that stimulation of biological CO2 fixation (via the nutrient upwelling) >>> more than offsets the upwelled CO2 degassing to the atmosphere, what's the >>> point? >>> -Greg Rau >>> >>> >>> >>>> A simple way to achieve this would be to force air down into deep >>>> pipes and allow it to bubble to the surface. The same principle is >>>> used in fishtanks to create upwelling water and increase the surface >>>> area for gaseous exchange. There's a tradeoff between little bubbles >>>> (for gaseous exchange) and big bubbles (to force mixing). >>>> >>>> Flow tubes would probably be necessary to create a defined upwelling >>>> column of water. These tubes would provide a reasonably good mount >>>> for a wind turbine or sea turbine, provided they could be anchored to >>>> the sea bed. The most obvious engineering problem I can think of is >>>> stability and resonances. >>>> >>>> What do other people think? >>>> >>>> A >>>> >>>> 2009/1/13 John Nissen <[email protected]>: >>>>> >>>>> Hi all, >>>>> >>>>> Could there be a case for geoengineering to increase sea "ventilation" >>>>> and >>>>> thereby increase CO2 absorption by the sea? (I'm thinking of those >>>>> millions >>>>> of wave-powered tubes suggested by Chris Rapley and James Lovelock to >>>>> bring >>>>> deep cool water to the surface.) >>>>> >>>>> http:// www. >>>>> guardian.co.uk/environment/2009/jan/12/sea-co2-climate-japan-environment >>>>> >>>>> --- >>>>> >>>>> >>>>> Sea absorbing less CO2, scientists discover >>>>> >>>>> David Adam, environment correspondent >>>>> The Guardian, Monday 12 January 2009 >>>>> Article history >>>>> >>>>> Scientists have issued a new warning about climate change after >>>>> discovering >>>>> a sudden and dramatic collapse in the amount of carbon emissions >>>>> absorbed by >>>>> the Sea of Japan. >>>>> >>>>> The shift has alarmed experts, who blame global warming. >>>>> >>>>> The world's oceans soak up about 11bn tonnes of human carbon dioxide >>>>> pollution each year, about a quarter of all produced, and even a slight >>>>> weakening of this natural process would leave significantly more CO2 in >>>>> the >>>>> atmosphere. That would require countries to adopt much stricter >>>>> emissions >>>>> targets to prevent dangerous rises in temperature. >>>>> >>>>> Kitack Lee, an associate professor at Pohang University of Science and >>>>> Technology, who led the research, says the discovery is the "very first >>>>> observation that directly relates ocean CO2 uptake change to ocean >>>>> warming". >>>>> >>>>> He says the warmer conditions disrupt a process known as "ventilation" - >>>>> the >>>>> way seawater flows and mixes and drags absorbed CO2 from surface waters >>>>> to >>>>> the depths. He warns that the effect is probably not confined to the Sea >>>>> of >>>>> Japan. It could also affect CO2 uptake in the Atlantic and Southern >>>>> oceans. >>>>> >>>>> "Our result in the East Sea unequivocally demonstrated that oceanic >>>>> uptake >>>>> of CO2 has been directly affected by warming-induced weakening of >>>>> vertical >>>>> ventilation," he says. Korea argues that the Sea of Japan should be >>>>> renamed >>>>> the East Sea, because it says the former is a legacy of Japan's military >>>>> expansion in the region. >>>>> >>>>> Lee adds: "In other words, the increase in atmospheric temperature due >>>>> to >>>>> global warming can profoundly influence the ocean ventilation, thereby >>>>> decreasing the uptake rate of CO2." >>>>> >>>>> Working with Pavel Tishchenko of the Russian Pacific Oceanological >>>>> Institute >>>>> in Vladivostok, Lee and his colleague Geun-Ha Park used a cruise on the >>>>> Professor Gagarinskiy, a Russian research vessel, last May to take >>>>> seawater >>>>> samples from 24 sites across the Sea of Japan. >>>>> >>>>> They compared the dissolved CO2 in the seawater with similar samples >>>>> collected in 1992 and 1999. The results showed the amount of CO2 >>>>> absorbed >>>>> during 1999 to 2007 was half the level recorded from 1992 to 1999. >>>> >>>>> >>>>> >>>>> Crucially, the study revealed that ocean mixing, a process required to >>>>> deposit carbon in deep water, where it is more likely to stay, appears >>>>> to >>>>> have significantly weakened. >>>>> >>>>> Announcing their results in the journal Geophysical Research Letters, >>>>> the >>>>> scientists say: "The striking feature is that nearly all anthropogenic >>>>> CO2 >>>>> taken up in the recent period was confined to waters less than 300 >>>>> metres in >>>>> depth. The rapid and substantial reduction ... is surprising and is >>>>> attributed to considerable weakening of overturning circulation." >>>>> >>>>> Corinne Le Quéré, an expert in ocean carbon storage at the University of >>>>> East Anglia, said: "We don't think the ocean is just going to completely >>>>> stop taking our carbon dioxide emissions, but if the effect weakens then >>>>> it >>>>> has real consequences for the atmosphere." >>>>> >>>>> --- >>>>> >>>>> >>>>> Cheers, >>>>> >>>>> John >>>>> >>>>>> >>>>> >>>> >>>>> >>> >> >> >> > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
